Die for pressure casting



Dec. 16, 1941. T. c. KORSMO DIE FOR PRESSURE cAsTING '4 Sheets-Sheet 1Filed Jan. 2, 1941 I Q: Zinbentor J (Ittornegs Dec. 16,1941. T. .c. KosMo I DIE FOR PRESSURE QASTING v Filed Jan/2, 1941 4 Sheets-Sheet 3 o Db Mg mm 0. WW m. w m ww 5 Dec. 16, 1941;

r. c. KOR'SMO DIE FOR PRE S SURE C ASTING File d Jan. 2, 1941 4Sheets--Sheet 3 3nventor (Ittornegs Dec;16, 1941. T. c. KoRsMo Y D I EFOR PRESSURE CASTING Fil'ed JanL 2, 1941 4 Sheets-Sheet 4 llllllllllll3nven bo z ba'om qihg (Ittornegs pacts was multiplied by Patented -Dec.16, 1941 Torbjorn C. Korsmo, M Madison-Kipp Corporation, corporation ofWisconsin Application January 2, 1941, Serial No.

adison, Wis., assignor to Madison, -Wis., a

. 8 Claims. (C1. 22-458) This invention relates todies for die castingmachines, and particularly to apparatus for pulling the core from a dieduring the opening movement of the die parts.

The invention is an improvement on the structure of the Korsm'o PatentNo, 2,033,036,issued March 3, 1936 and extends the range of utility ofthe mechanism of that prior patent. In the prior Korsmo patent the corepulling stress is delivered to the core-carrying slide through acarriage which is pivoted to the slide at a point intermediate its endsand has two pairs of rollers, one at each of its opposite ends, therollers running, in pairs, on two sets of cam tracks which are supportedby; the combination bars forming a part of the die casting machine. Thecams are so designed that as the movable part of the die retreats fromits closed position one end of the carriage is shifted in a direction topull the core, while the other one moves in a neutral path and'serves asa fulcrum. Then the other end of the carria'geis moved out while thefirst serves as a fulcrum, after which both ends of the carriage areguidedto the extreme outward position in oblique parallel cam grooves.Thus the core-carrying slide was given two successive opening impactswhich broke the core away from the casting, and the force of the im thelever effects of the carriage in its successive pivoting motions.

This mechanism has proved highly satisfactory in service. The presentinvention simplifies its construction cons'derably and extends itsutility so that it is now peculiarly effective where heavy cores must behandled. In the-Korsmo patented device the closing movement of the corewas effected through the carriage and this required an adjustment ofapart of the cam track. This adjustment, and the fact that the camtracks were mounted on the e rather than on the die, complicated theprocedure in mounting the die in the machine. In

the improved embodiment forming the subject 6 of the present inventionthe cam tracks are so contrived that they can be mounted on the fixedportion of the die. Thus the g the die in the machine assures correctlocation of the cam tracks. Further, the carriage mechanism and the camtracks with'which it meets perform only the function of withdrawing thecore. There is a separate cam which performs the function of returningthe core to its operative position as the die closes. This'second camhas only a light duty to perform, fected by the shocks delivered throughthe car'- is never afriage during the core pulling function, and'con-vsequently can be manufactured with precision and requires theconstruction is simplified, installation of the a no provision foradjustment. Thus dies is simplified, operation is improved, and theability to handle heavy cores is enhanced.

There are other features of novelty and utility more or less related tothe features above-mentioned and these will become apparent inconnection with the detailed description of a preferred embodiment ofthe inventionwhich will now be given with reference to the accompanyingdrawings.

In the drawings: 1

Figure l is a plan view showing the positions assumed by the parts whenthe die is closed and the cores are in their operative positions.

Fig. 2 is a similar view showing the movable die part fully withdrawnand the cores withtracks shown in the position of Fig. 1

' slide and core.

started. Fig. 10 shows mere mounting of drawn to their limiting outwardpositions.

Fig.3 is a section on the line 3-3 of Fig. 1. Fig. 4 is a side elevation.of the'carriag'e and and viewed in the direction'of the arrow marked 4on Fig. 1. Fig. 5 is a fragmentary perspective view of the carriage, theupper end of the core carrier slide,

.and the tracks on which the carriage runs.

Fig. 6 is a perspective viewof the core carrier Figs. 710, inclusive,are fragmentary views of the core actuating mechanism showing successivesteps during the opening motion of the die.

Fig. 7, shows the die closed. Fig.8 shows the die carriage ready todeliver startingto open and the the opening impact to the positionassumed the core. Fig. 9.shows V the wide open position.

Referring first toFigs. 1 to. 3, the general com-. ponents of the diecasting machine will be identified to indicate the environment in whichthe inventionv is used.

A portion of the main housing of the machine is indicated at ll, whilel2 represents .the socalled hot plate against which the fixed half ofthe die is mounted. This fixed halfincludes a main body l3 and twoinserts, namely, the insert it which forms half of the die proper, andtheinsert l5 which forms half of the injection chamberin which themolten material, for example housing I I are'two molten metal, issubjected to pressure to force" after the core hasbeen 7 between the hotplate and mainhousing. Guided on these is a carriage I! which isactuated by the ram l9. Theends' of a the carriage 8 are connected tothe remote end pressure chamber.

An ejecting mechanism is mounted in the interval between the two forwardprojections 22 and comprises two releasably connected plates 26 and 21.The plate 21 carries the ejector pins 28. These work through aperturesin the movable die component and are normally retracted as shown in Fig.3. Theyare urged to their retracted position by a plurality of coilcompression springs one of which appears at 29. In

I order to operate the ejector pins 28 when the die :is wide open, fouradjustable studs 3| are threaded in the housing II and are so set thatshortly before the die reaches fully open position the ends of the studsstrike the plate 26 and-by preventing the retreat of the plate 26 to theright while the movable die half is still retreating to the right, causethe pins 28 to protrude through the mold cavity in the die and strip thecasting.

The springs 29 are not relied upon to cause retreat of the ejector pins28 from the die cavity. Positive actuating means are provided and willnow be described.

. Mounted between the members 22 and against the forward face of thecarriage I8 is a housing 32 in which is journaled a vertical shaft 33.This shaft carries an elongated pinion 34 which extends nearly itsentire length. (See Fig. 1.) This pinion meshes with two racks 35 fixedon and projecting rearwardly from the plate 26. Thus any motion of theplate 26 relatively to the movabledie portion entails rotation of theshaft 33.

Fixed to the upper end of the shaft 33 is a crank arm 36, which carriesa roller 31. This bars 56 is pivoted on a pin 51 which passes rollerengages the sideof the track 38 fixed to Y the combination bar 39. Thecombination bar is an interchangeable element of the machine used tosupport any of various cam mechanisms which may be required forparticular dies. The major portion of the active face of the track 38engazed by the roller 31 is parallel with the motion of the carriage |8but the end of the track is beveled as indicated at 4|. 4| permitsswinging motion of the crank 36 (see Fig. 3) after the adjustable pins3| have engaged the plate 21. Thus, when the die is nearly fully open,the bar 39 permits protrusion of the ejector Pins.

During initial motion in die closing direction the roller 31 travels upthe inclined portion 4| and retracts the ejector pins positively,irrespective of the action of the spring 29. This retraction occurs inthe first portion of themotion and the pins are held retracted'in allpositions between and including this and die closed position.

The plunger indicated at 42 is'the plunger used to force molten metalinto the die.

The parts so far described will be recognized as components of the diecasting machine described" and claimed in Korsmo Patent No. 2,033,036.

The cavity in the die inserts l4 and 24 re- The beveled portion core 43and a much larger core 44 which happen to be axially aligned. Both ofthese must be retracted as the die opens. The small core 43 is mountedon a slide 45 which is guided-in the movable die part 23 to move in adirection transverse to the motion of the carriage l8. It is actuated byan inclined cam bar 46 which is fixed in the fixed die part l3 and whichcoa'cts with a slot 41 in the slide 45. A simpleinclined cam bar issuflicient for the small core 43. Since no novelty is claimed for thisparticular arrangement, further description appears to be unnecessary.

The large ,core 44 whose operating mechanism includes the subject matterof the present invention is formed on the inner end of a slide 46 whichis guided on the movable die member 23 and projects horizontallytherefrom. The form of this slide 48 is clearly shown in Fig, 6. Itcarries a block 49'which seats against the two portions of the die whenthe latter is closed and which has on its outer face an inclinedreaction or cam follower surface 5| which conforms in angle to andengages the inner faces of two oblique cam bars 52 and 53 which aresustained on the fixed die member l3. s

The surface 5| coacting with the bars 52 and.

two bars and extend approximately half the.

width of each bar. See Figs. 4 and 5. g

A small carriage made up of two identical side through the bars andthrough the bearing 58 in the upper end of the slide 48. The bars 56 aretied together by a cross member 59 and by two roller-carrying shafts 6|and 62, the shaft 6| being longer than the shaft 62 and being providedwith rollers 63 which extend the full width of the track members 52 and53. The shorter cross shaft 62 carries two shorter rollers 64 which arealso located closely adjacent the bars 56 but do not extend the fullwidth of the bars 52. and 53. The construction is such that the rollers63 are guided in a straight path from end to end of the bars 52 and 53,whereas the rollers 64 follow depressions or dips 54 and 55. The surfaceon which rollers 64 roll is clearly indicated in dotted lines on Fig. 1.

Referring now to Figs: 7 to 9 it will be observed that the parts are soproportioned that when thedie parts are closed (Fig. 7) the rollers 64are atthe-entrance to the depressions 54 and 55 and the rollers 63 donot even contact the bars 52, 53. The entrance contour of thesedepressions is approximately parallel with the path of travel of thecarriage l8. Thus, as the die parts begin to open (see Fig. 8), therollers 64 are permitted to move in a path parallel with the path of thecarriage I8, whereas the rollers 63 are forced to move in a path obliqueand outward relatively to the path of the carriage l8.

It will be observed that the pin 51 is closer to the shaft 62 than tothe shaft 6|, and conse-- quently the carriage serves as a lever,developing a force ratio (which in the example illus- ,trated is about 3to 1 in an opening direction upon the slide 48. The initial withdrawingimpact is delivered to the core after the die parts have opened slightlyas indicated in Fig. 8. In

the position of Fig. 9 the force multiplying leverage action is stilleffective but will shortly diminish as the rollers 64 start to ride outof the depression. The positions assumed by the parts, in the full openposition of the die parts, ar clearly indicated in Fig. 10.

It will be observed therefore that during the initial opening of thedie-the core 44 is not shifted, but after partial opening, approximatelyin the position shown in Fig. 8, an opening impact is suddenly deliveredto the core-carrying slide 48. carriage continues for a period until thedie has opened a little more than is indicated in Fig-9. Th finalopening movement of the die occurs without the force multiplying effecton the carriage.

In the closing movement the beveled surface i actsas a closing cam sothat the carriage :has no closing effect. start to enter the depressions54 and 55, there is clearance between the rollers on the carriage andthe guide track. Thus the cam bars 52, 53

1 need not be adjustable. If the impact delivered through the carriaghas any disturbing effect it will affect only the opening movement whichneed not be extremely precise. The closing movement of the core will notbe affected and is positively controlled by the design of the member 49and the inner faces of the bars 52 and 53.

What is claimed is: 1. The combination of a casting die comprising atleast twoparts; means for producing relative motion between said partsin a definite path toopen and close the die; a core guided in one partof thedie to move in a path suitable for withdrawal of the core from acasting formed in the die; cam means on the other part of the die andformed with two distinct cam tracks of different configuration; and twodistinct cam followers associated with said core, one coacting with onecam track in the opening motion of the die to withdraw the core and theother coacting with the other cam trackin the closing motion of the dieparts to return and accurate1y position the core.

2. The combination of a. casting die compristive motion between saidparts in a definite path to open andclose the die; a core guided in onepart of the die to move in a path suited to the withdrawal of the corefrom -a casting formed in the die; cam. means on the other part of thedie and comprisingtwo distinct cams, namely, a

The force multiplying action of the withdrawal of the core in the die;cam means on the other part of the In fact, after the rollers 64 catedas to cause the carriage to function as a lever after the die has partlyopened and then to' deliver the intial opening impact to the core.

5.The combination of a casting die comprising at least two parts; meansfor producing rela tive motion between said parts in a definite path toopen and close the die; a core guided in one 7 part of the die to movein a path suited to the from a casting formed die and comprising twodistinct cams, namely, a straight line core restoring cam and a coreextracting cam, said restoring and extracting cams .being arrangedobliquely to said path of relative movement of the die parts and saidextracting cam comprising two tracks of differing configuration asbetween themselves; a beveled cam follower connected with thecore andcoacting with said restoring cam in theclosing motion of the die partsto return and accurately position the core; and a cam follower carriagepivoted intermediate its ends to said core and having adjacent itsopposite ends sets of rollers which respectively coact with saiddifiering tracks in the opening motion of 6. The combination of acasting die comprising .at least two parts, one of which is fixed; meansfor moving another part of the diein a definite path to open and close.the die; a core guided in said moving part of the die to move in a. pathsuitable for withdrawal'of the core from a'casting at least two parts;means for producing relaing formed in the die; fixed cam means with twodistinct cam tracks of different configuration arranged obliquely tosaid path of movement of the movable 'die part; and two distinct camfollowers operatively connected with said core, one of saidfollowersiincluding lever-type force-multiplying means coact-ing withone cam track in the opening movement of the die partto withdraw the;core, and the other follower including a beveled surface coasting withthe other cam track in the closing movement of the die part to returnand accurately position the core. 7. The combination of a casting diecomprising at least two parts, one of which is fixed and the corerestoring cam and a core extracting :cam,

said extracting cam comprising two tracks 'of diflering configuration asbetween themselves; a cam follower connected with the coreand coactingwith said restoring cam in the closing motionof the die parts to retumand accurately position the core; and a cam follower carriage other ofwhich is movable; means for moving the movable part of said die in adefinite path to open and close the die a core slide having a core partand guided in said movable die part to move in apath suited to thewithdrawal of the core part from the casting formed in the die; fixedcam means comprising two distinct cams, name- 1y, 9. oorerestoring camand a core extracting cjam, said restoring and extracting cams beindisposed obliquely to said path of the movable die part and saidextracting cam comprising two tracks of different coniilzuration asbetween themselves; a cam follower located on the slide and including aninclined surface coacting with said restoring,cam; and a cam followercarriage pivoted intermediate its ends to said core slide andhaving'adj'acent rollers which respectively coact ing tracks.

8. The combination of a casting die comprising at least two parts; meansfor producing relative motion between saidparts in a definite path towith said differthe die to withdraw the core.

formed its opposite ends sets of open and close the die; a core slidehaving a core and guided in one part of the die to move in a path suitedto the withdrawal of the core from a I casting formed in the die; cammeans comprising a pair of spaced'cam bars rigidly supported 5 on theother part of the die and projecting outwardly therefrom across theseparation line of the die and obliquely to said relative path of motionof the die parts, the inner obliquely-disposed straight edges of the cambars together 10 forming a core restoring cam track, each cam bar havinga depressed cam surface along its outer edge, said depressed surfacestogether and the obliquely-disposed straight outer edges oi the cam barstogether forming two core extracting cam tracks; beveled-surface camfollower means located on the slide and coacting with said re--

